diff options
Diffstat (limited to 'fs/btrfs/extent-tree.c')
| -rw-r--r-- | fs/btrfs/extent-tree.c | 20 |
1 files changed, 20 insertions, 0 deletions
diff --git a/fs/btrfs/extent-tree.c b/fs/btrfs/extent-tree.c index 30a5094..db996f0 100644 --- a/fs/btrfs/extent-tree.c +++ b/fs/btrfs/extent-tree.c @@ -731,6 +731,7 @@ u32 btrfs_count_snapshots_in_path(struct btrfs_root *root, u64 found_owner; u64 root_objectid = root->root_key.objectid; u32 total_count = 0; + u32 extent_refs; u32 cur_count; u32 nritems; int ret; @@ -767,6 +768,7 @@ again: } item = btrfs_item_ptr(l, path->slots[0], struct btrfs_extent_item); + extent_refs = btrfs_extent_refs(l, item); while (1) { l = path->nodes[0]; nritems = btrfs_header_nritems(l); @@ -800,10 +802,28 @@ again: total_count = 2; goto out; } + /* + * nasty. we don't count a reference held by + * the running transaction. This allows nodatacow + * to avoid cow most of the time + */ + if (found_owner >= BTRFS_FIRST_FREE_OBJECTID && + btrfs_ref_generation(l, ref_item) == + root->fs_info->generation) { + extent_refs--; + } } total_count = 1; path->slots[0]++; } + /* + * if there is more than one reference against a data extent, + * we have to assume the other ref is another snapshot + */ + if (level == -1 && extent_refs > 1) { + total_count = 2; + goto out; + } if (cur_count == 0) { total_count = 0; goto out; |